Only lightly used! Tried it once and decided to get an upgraded version. Works perfectly. Industry's best aperture ring covers a 8-stop range markings, clearly indicating actual number of f-stops. Compatible with both Nikkor G lens & F lens (include non-AI & AI lens mounts). All metal structure, with excellent opticals (5 elements/4 groups) Increase maximum aperture by 1 stop. Increase MTF. In common lens adapters, cropping effect occurs in all APS-C digital cameras with 1.5x magnification. This adapter reduces focal length to 0.71x , to adjust the image size to near 1:1 so that the focal length of the image is close to actual focal length of the lens, e.g. 50mm x 1.5 x 0.71 = 53.25mm. The tripod foot is detachable and compatible with Arca Swiss, Markins, Photo Clam ball heads. Note: When the Speed Booster is used with Sony A7, A7R or A7S the camera is required to be used in the "APS-C Size Capture" mode. Tips: Before mounting your lens to the adaptor, please make sure that the f-stop of aperture ring on the adaptor is turned to "7" (i.e. mounting your lens to the adaptor while only the aperture ring in the adaptor is full closed.). Remark: This mount is manual aperture control. It does NOT support electronic aperture control. Work for: -Nikkon G lens & F lens (include non-AI & AI lens mounts) -Sony E Mount, NEX-3N NEX-6 NEX-5R NEX-F3 NEX-7 NEX-5N NEX-5C NEX-C3 NEX-3 NEX-5